Dynamic frequency scaling is a technique that automatically adjusts the frequency of a processor at runtime. An increase in the operating frequency of a processor can ramp up the computing performance. However, a frequency increase means that power consumption of the processor also increases, as the power consumption in an integrated circuit is computed as: P=C×V2×F, where P is the power, C is the capacitance being switched per clock cycle, V is the voltage and F is the frequency. Some modern computer systems have a built-in management framework to manage the tradeoff between performance and power consumption. For example, the management framework may determine at runtime whether to increase or decrease the operating frequency, and whether to activate or deactivate a processor core, in order to satisfy system performance requirements or to save power.
In a multi-cluster system that has multiple processor types, the management framework needs to take into consideration both power consumption and performance of each processor type. If only one processor type is allowed to operate at a time, the processing capacity of the other processor types is under-utilized and may not satisfy a high workload demand. In a system that allows multiple processor types to operate at the same time, the management framework needs to have a strategy for optimizing efficiency and low power operations.
Therefore, there is a need to improve the power and performance management in a multi-cluster system that has multiple processor types.